Understanding HF Propagation

Рет қаралды 89,011

Күн бұрын

This video is an introduction to the fundamental concepts of HF propagation, with special emphasis placed on skywave propagation and the role of the ionosphere.
More HF educational resources: www.rohde-schwarz.com/us/camp...
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Пікірлер: 64

@BryanWicks Жыл бұрын

This presentation should be incorporated into the initial training of anyone wishing to get their ham license. I found the information to be concise, articulated well, sufficiently illustrated, and no needless fluff. Anyone actively interested in the topic will be well served with this introduction into the concepts discussed. Thank you for uploading this video; I only wished that I had seen it much sooner!

@pauldenisowski Жыл бұрын

Thank you!

@y_x2 2 ай бұрын

Yes but at a much lower speed.

@solarmfolijezastakla 2 жыл бұрын

No matter which ham radio class you are and how much experience you have this video should be listened many times.

@TheTechPrepper 3 жыл бұрын

What a wonderfully executed overview of HF propagation. I wish I had seen this video while studying for my General license. Clear, concise and pure gold.

@outwithradios8145 3 жыл бұрын

after 44 years of HF ops it still makes me feel like a child when i get long DX,what a great feeling

@DoronTirkel Жыл бұрын

Anyone who is seriously interested in the subject will benefit from this introduction to the concepts covered. The information is articulated and illustrated clearly. Doron, 4X4XM

@pauldenisowski Жыл бұрын

Thank you for the feedback!

@redsky1433 2 жыл бұрын

Excellent presentation. Clear and to the point. The details of HF propagation can get quite complicated but this introduction is spot on.

@pauldenisowski Жыл бұрын

Thank you!

@lpark8 3 жыл бұрын

Wow. Great presentation. It covers a lot of ground. I’m gonna have to listen to it again. Thank you!

@garylanders1470 Жыл бұрын

Great presentation! Thank you kindly

@chrismeagher7237 3 жыл бұрын

Excellent presentation with simple, effective graphics. Thanks

@pauldenisowski 3 жыл бұрын

Thanks for the feedback!

@Ambatukamhorifooq Жыл бұрын

Amazing presentation, thank you!

@pauldenisowski Жыл бұрын

Thanks!

@konnorkuznetsov1035 3 жыл бұрын

Excellent presentation! This is perfect for my new ham friends, thank you!

@victorb22622 Жыл бұрын

Very nicely described.refrashed my knowledge of hf prepogation

@pauldenisowski Жыл бұрын

Thank you!

@m_rehanbutt 2 жыл бұрын

Good Presentation

@m_rehanbutt 2 жыл бұрын

I luckily trained from R&S Germany

@bijohnAdams 3 жыл бұрын

It is informative indeed... Thanks...

@GraceKataliko 20 күн бұрын

You're the best 👍👏👏👏

@philsimpson6093 3 жыл бұрын

Excellent presentation

@rfmonkey4942 3 жыл бұрын

"HF the only way to fly" regards from vk3 and remember "when triodes are glowing electrons are flowing"

@philmonat9352 24 күн бұрын

Very Good !

@skydivingcomrade1648 Жыл бұрын

Great video

@RogerBravo12 2 жыл бұрын

Really good presentation 👏🏼 so kind of R&S to set up this videos of how radio and some antennas works. Sended this video to some friends that are interested in radio 💪🏼 Best 73/ Roger

@pauldenisowski 2 жыл бұрын

Thanks! In addition to test and measurement instruments, we also design and manufacture HF radios, amplifiers, antennas, etc. (although mostly for the commercial and military / government markets, not really for amateurs). Thanks again for the feedback! 73, Paul KO4LZ

@RogerBravo12 Жыл бұрын

@@pauldenisowski Nice to hear 😀 I have the privilege to use some R&S instruments in my work 👍🏻 de Sa1ckr

@successsecret871 Жыл бұрын

excellent

@2ysur 3 жыл бұрын

Well done.

@boim9312 2 жыл бұрын

Great explanation 🥳

@storaman12 2 жыл бұрын

Excellent

@muhammadsoleh9148 Жыл бұрын

Good English presentation...

@pauldenisowski Жыл бұрын

Thanks - it's my native language :)

@drankurbaruah 3 жыл бұрын

How was sun spot info collected 400 years ago? Thanks for the awesome video. Learnt a lot. 🙏

@pauldenisowski 3 жыл бұрын

Visual observation. There are actually some manuscripts from that time that show sunspots being recorded (see image at link below, from the year 1611). Not sure that they followed the modern precautions /warning regarding looking at the sun. :) Thanks! images.skinnerinc.com/full/920/1217920_view%2016_16.jpg

@drankurbaruah 3 жыл бұрын

@@pauldenisowski Damn that is interesting!!! Thank you so much!!!

@G0FUW 3 жыл бұрын

One of my students pointed out that the statement at 10:43 says that when the RF passes through the ionosphere and into space, that is the critical frequency. However, all the textbooks I have say the critical frequency is the highest frequency that is reflected (refracted) back to ground. Is there another definition in use?

@pauldenisowski 3 жыл бұрын

That's a great question. I suppose you could avoid ambiguity by defining it as the frequency above which signals pass into space and below which signals are refracted back (laughs).

@tixilx 2 жыл бұрын

Critical frequency is the highest magnitude of frequency above which the waves penetrate the ionosphere and below which the waves are reflected back from the ionosphere. It is denoted by "fc". Its value is not fixed and it depends upon the electron density of the ionosphere.

@G0FUW 2 жыл бұрын

@@tixilx that was my understanding too.

@kartiniganesha6741 3 жыл бұрын

In maximum condition, how must the most longer distance range for communication in HF frequency?

@pauldenisowski 3 жыл бұрын

HF can be (and regularly is) used to communicate between any two points on the globe, so maximum range is half the Earth's circumference :) In practice, the maximum achievable distance is function of many factors, including the current state of the ionosphere, the chosen frequency, the Tx and RX antenna characteristics and orientation, the Tx power, the Rx sensitivity, noise levels, modulation type, etc. During peaks in the 11 year solar cycle, worldwide communication can often be accomplished with less than a watt of power and a very modest antenna, whereas at the "troughs," it can be very challenging to reach certain stations without very high power levels and very good antennas.

@WW5RM 3 жыл бұрын

@@pauldenisowski slightly more than half as the RF horizon is more than visual horizon. Radio waves bend. Plus multi hop and long path happen daily. Many factors can give more range than just half. WW5RM

@WW5RM 3 жыл бұрын

My furthest QSO is 9100 miles / 14,650 km. Jan - ZS6HA in South Africa. I am in Texas. WW5RM

@pauldenisowski 3 жыл бұрын

@@WW5RM Yes, of course. :) Long-path is an excellent example of where the total path length will be longer than the "short part" to the destination: There are many occasions where or reasons why long-path may be the best way to reach a given station. And as you also point out, the actual path length will depends on the number of hops, etc. I interpreted the question to be: "what is the max possible distance between transmitter and receiver when using HF?" and since HF does allow (under the right conditions) communications between any two points on the globe, my somewhat tongue-in-cheek answer was "half the Earth's circumference" :) Thanks for pointing out that the actual max propagation distance can be considerably longer. 73!

@pauldenisowski 3 жыл бұрын

@@WW5RM Impressive! The long path between EM23 and KG53 would be about 15,800 miles :)

@RichCasey 3 жыл бұрын

Thanks for a great presentation! Will pass along to other ham operators. N5CSU

@RohdeundSchwarz 3 жыл бұрын

Hi Rich, thanks for the recommendation.

@pauldenisowski 3 жыл бұрын

Thanks Rich! 73 de Paul, KO4LZ

@elkierose6228 Жыл бұрын

How do you prevent HF signals.

@raghumehra4949 Жыл бұрын

Anda boleh memilih untuk salah satu daripada hadiah di atas

@pauldenisowski Жыл бұрын

Pemberian ilmu adalah anugerah terhebat :)

@agonizedanguish6267 Жыл бұрын

Giggity giggity Recon

@richardweir5497 Жыл бұрын

question about slide 23. you stated if the MUF becomes higher than the LUF @17:38. did you mean if the LUF becomes higher than the MUF??

@tonyturtle5805 3 жыл бұрын

the picture depicts lines of electromagnetic force but they tend to make our mins believe the signals are shot out like bullets,but its really a giant omni directionals disruption of molecules from the antenna envoping in an omni directional patteren like a bomb going off,the molecule stays put but transfers the vibration to the nieghboring molecule like dominoes,f going deep into the ground and reflecting back upwards or refracting from the ground becuase of the different meduim opposedt to the atmosphere then reaching up into the inonsphere where it then refracts back to earth where it could end up anywhere there is a least resistant path to do so ,i think anyway ,every time we hit the key we ignite a giant vibration of the molecules like a pattern of an explosion ,with everything staying put

@RichardKCollins Жыл бұрын

Maybe you should make a video to share this particular vision of how things work. The words are not quite enough.